21124221123 has 4 divisors (see below), whose sum is σ = 28165628168. Its totient is φ = 14082814080.

The previous prime is 21124221121. The next prime is 21124221133. The reversal of 21124221123 is 32112242112.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 21124221123 - 2¹ = 21124221121 is a prime.

It is a super-2 number, since 2×21124221123² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21124221123.

It is not an unprimeable number, because it can be changed into a prime (21124221121) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3520703518 + ... + 3520703523.

It is an arithmetic number, because the mean of its divisors is an integer number (7041407042).

Almost surely, 2^21124221123 is an apocalyptic number.

21124221123 is a deficient number, since it is larger than the sum of its proper divisors (7041407045).

21124221123 is an equidigital number, since it uses as much as digits as its factorization.

21124221123 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7041407044.

The product of its digits is 384, while the sum is 21.

Adding to 21124221123 its reverse (32112242112), we get a palindrome (53236463235).

The spelling of 21124221123 in words is "twenty-one billion, one hundred twenty-four million, two hundred twenty-one thousand, one hundred twenty-three".